138318181225505 has 8 divisors (see below), whose sum is σ = 166130413553832. Its totient is φ = 110555480924928.

The previous prime is 138318181225501. The next prime is 138318181225529. The reversal of 138318181225505 is 505522181813831.

It can be written as a sum of positive squares in 4 ways, for example, as 17479431467281 + 120838749758224 = 4180841^2 + 10992668^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138318181225505 - 2² = 138318181225501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138318181225501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12383000792 + ... + 12383011961.

It is an arithmetic number, because the mean of its divisors is an integer number (20766301694229).

Almost surely, 2^{138318181225505} is an apocalyptic number.

It is an amenable number.

138318181225505 is a deficient number, since it is larger than the sum of its proper divisors (27812232328327).

138318181225505 is a wasteful number, since it uses less digits than its factorization.

138318181225505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24766013875.

The product of its (nonzero) digits is 2304000, while the sum is 53.

The spelling of 138318181225505 in words is "one hundred thirty-eight trillion, three hundred eighteen billion, one hundred eighty-one million, two hundred twenty-five thousand, five hundred five".